DIY electric water pump - on the cheap

[Daox]

Nor would I. Thus the question.

[sqidd]

Originally Posted by oil pan 4

I would never run the engine with out the coolant pump turning.

My 2007 Mustang runs a LOT without the coolant pump turning.

That said you wouldn't be able to set up like I am with a A/C clutch (well you could, but it would be silly). It pretty much as to be electronically controlled.

[Daox]

You're running the Davies Craig controller, right? According to their site, that runs the pump (albeit slowly) continuously, at anything more than 23° F (-5° C). Below that it is pulsed at an oddly low rate.

[oil pan 4]

I have low speed setting for my electric coolant pump but its never stopped.
With all the clamping load on the head and block and the possibility to have extreme temperature differentials I would rather not add to that stress with high differential temperatures between the head, block and parts within the head.

"10 seconds on, 30 seconds off" "10 on, 10 off"

Nope I'll pass.
Its almost as if they are unaware that different parts of the engine heat up faster than other parts.

My low speed is about 6 volts.

[sqidd]

Originally Posted by Daox

You're running the Davies Craig controller, right? According to their site, that runs the pump (albeit slowly) continuously, at anything more than 23° F (-5° C). Below that it is pulsed at an oddly low rate.

Your not reading that quite right. It pulses the pump on/off/on/off, etc until it gets to within 5deg C of the set point (this would be your thermostat point). 10 on, 10 off. Then it ramps up. When I am doing something like cruising down the freeway I can watch my temp readout fluctuate about 5-7deg as the pump turns itself on/off. In low load higher speed (75mph on the freeway) the cooling system is working so good that you don't want the pump running all the time because then the motor would be too cold.

I'm betting you would find that in a more OEM type cooling system, especially one where the grill is blocked off, the pump will probably run almost all the time.

[sqidd]

Originally Posted by oil pan 4

I have low speed setting for my electric coolant pump but its never stopped.
With all the clamping load on the head and block and the possibility to have extreme temperature differentials I would rather not add to that stress with high differential temperatures between the head, block and parts within the head.

"10 seconds on, 30 seconds off" "10 on, 10 off"

Nope I'll pass.
Its almost as if they are unaware that different parts of the engine heat up faster than other parts.

My low speed is about 6 volts.

Well, I'm pulling over a 1000hp at the wheels out of a 4.6L motor and nothing has gone wrong yet. It gets used a LOT harder than any drag car does. A 20min roadrace session is about 120 drag passes. When I drive the car at the track I do about 5-6 session like that a day. And the last time I went to the track I drove it there and back, 3hrs each way.

If I'm not breaking stuff, you guys won't.

[Daox]

Aaah, but you've removed your thermostat, haven't you? I was not planning on doing that.

I'd like to run the pump at a very low rate when my block heater is hooked up so that the entire engine is warmed when I go to start it.

[serialk11r]

How much power would your pump use at 6V anyways? I feel like it can't be more than a lightbulb or two.

The way I'd do it is probably buy one of those single channel PWM fan controllers, wire in a bigger MOSFET and maybe a capacitor (just in case the pump isn't happy with the PWM, it can affect longevity), and have it connected to the gas pedal so that it speeds up when you put higher loads on the engine, and have it "idle" at 6V when you're not on the gas.

To save even more money you could wire up a PWM controller yourself but I hate trying to figure out more complicated circuits.

[sqidd]

Originally Posted by Daox

Aaah, but you've removed your thermostat, haven't you? I was not planning on doing that.

I really like running no T-stat. It's the biggest/smallest restriction on the system.

I'd like to run the pump at a very low rate when my block heater is hooked up so that the entire engine is warmed when I go to start it.

Oh, I got lost somewhere. So you want to run the water around before you start the motor? Novel idea. Pre-heat the block, then circulate the water to the trans and warm that up too. Then start the car. I like that.

You linked a pic a few pages back but i'm not sure if that is what you decided you were going with. How are you planning on heating the trans with the water again? What sort of heat exchanger setup?

Also a few questions regarding another idea I was thinking of:

Does the OEM cooling system use a internal bypass when warming up? Or a external bypass. Or no bypass at all? Do you have any pics of how the cooling system runs and where the T-stat is at?

[BobS]

I ran my V6 for a full year without an electric fan, including 70 mph on the Interstate and only had problems when I got caught in minor in-town traffic jams. And I live in Florida. But I had removed the Tstat prior and I drive conservatively. I know it's a different situation, but I believe that as long as the water is moving through the system at a reasonable rate, that the change in radiator effectiveness will compensate for increased speed. But I would still like a cockpit switch that doubles the voltage as needed.